1. Field of the Invention
The present disclosure generally relates to a transmission device, and in particular, to a continuously variable transmission.
2. Description of the Related Art
Technically, the continuously variable transmission (CVT) is configured to transmit power through metallic belt and the roller having the variable diameter. The effective gear ratio of the CVT varies infinitesimally between a maximum value and a minimum value to achieve the function of step-less transmission. Compared with the other mechanisms designed with a finite amount of gear ratios, the input shaft of the CVT can be maintained at constant angular velocity to generate output angular velocity in a certain range.
For the sake of effectively transmitting power, the slippage between the metallic belt and rollers of the CVT are not allowed. In addition, the operations of the metallic belt and the rollers generate a lot of heat; the additional heat caused by the slippage may burn or cause serious damage to the internal components of the CVT. In order to increase the static friction, pressure may be exerted to the metallic belt and rollers. However, if the friction is increased, the efficiency of power transmission reduces and the fuel consumption increases accordingly.